Blood

Blood Facts Normal healthy adult has 4-6L of blood (~8% of body weight) Normal pH 7.35 – 7.45 Components of blood are plasma, erythrocytes (red blood cells), leukocytes (white blood cells), and platelets

Functions of Blood Distribution – transports oxygen, nutrients, metabolic wastes, and hormones Regulation – maintaining body temperature, normal pH, and adequate fluid volumes Protection – prevention of blood loss and infection

Blood Sample

Composition of Plasma Water (90%) – dissolving and suspending medium; absorbs heat Proteins (8%) Albumin (liver) - exerts osmotic pressure to maintain water balance between blood and tissues Alpha and beta globulins (liver) – help transport lipids, metal ions, and vitamins Gamma globulins - antibodies

Composition of Plasma Proteins (cont’d) Clotting proteins (liver) – fibrinogen and prothrombin Others – enzymes, antibacterial proteins, hormones Nitrogenous wastes – urea, uric acid, creatinine, ammonium salts

Composition of Plasma Nutrients – glucose, amino acids, fatty acids, glycerol, triglycerides, cholesterol, vitamins Electrolytes – sodium, potassium, calcium, magnesium, chloride, phosphate, sulfate, bicarbonate (maintain osmotic balance and pH) Respiratory gases – oxygen and carbon dioxide

Erythrocytes – RBC,s Transport respiratory gases – hemoglobin is 97% of RBC contents oxyhemoglobin – bright red deoxyhemoglobin – dark red Adult cells have no nucleus Shape is a biconcave disc Lifespan 120 days

Erythropoesis – regulation and production of RBC’s ~5 million RBCs per cubic millimeter of blood

Leukocytes – White Blood Cells Defend the body against bacteria, viruses, parasites, toxins and tumor cells Normally 4,800-10,800 WBCs per cubic millimeter of blood Adult cells have a nucleus

WBCs have Ameboid movement Diapedesis

Chemotaxis – WBCs are attracted by chemical signals from damaged cells or other WBCs http://www.youtube.com/watch?feature=player_detailpage&v=ZUUfdP87Ssg chemotaxis.ram

Immature rbc’s and wbc’s are found in bone marrow

Types of leukocytes Neutrophils – phagocytize bacteria Multilobed Nucleus Inconspicuous Granuoles

Types of leukocytes Eosinophils – kill parasitic worms, destroy antigen/antibody complexes, inactivate inflammatory chemicals of allergy Bilobed Nucleus Red Granuoles

Types of leukocytes Basophils – release histamine (a vasodilator) and attract other wbc’s Lobed Nuceus Purple Granuoles

Types of leukocytes Lymphocytes – mount immune response by direct cell attack or via antibodies Spherical nucleus

Types of leukocytes Monocytes – phagocytosis; develop into macrophages in tissues Kidney or U-shaped Nucleus

Platelets Cell fragments that hold chemicals involved in the clotting process

Steps in Hemostasis Blood vessel is injured Vascular spasm is triggered by chemical released by platelets and damaged cells – causes vasoconstriction

Steps in Hemostasis Platelet Plug Formation – platelets swell, form spikes and adhere to exposed collagen fibers in damaged blood vessel

Steps in Hemostasis Coagulation or Blood Clot formation Platelets release thrombokinase, an enzyme that starts clot formation

Normocytic – normal size erythrocytes Normochromic – normal amount of hemoglobin (some central pallor)

HYPOCHROMIC HYPERCHROMIC

Macrocytic vs. Microcytic RBC’s

Anisocytosis and Poikilocytosis

Stomatocytes May be seen in liver disease or electrolyte imbalances

Target Cells May be seen in hemolytic anemias

Burr Cells may indicate electrolyte imbalance or uremia

Spherocytes May be seen in certain anemias and severe burns